Systems and methods for proximal control of a surgical instrument

ABSTRACT

An instrument chassis for a robotic surgical system includes a bridge member, a first instrument guide member configured to receive a first surgical instrument, a second instrument guide member configured to receive a second surgical instrument, wherein each of the first instrument guide member and the second instrument guide member is moveably coupled to the bridge member such that each of the first instrument guide member and the second instrument guide member is moveable in at least one degree of freedom relative to the bridge member, and a central instrument guide member coupled to the bridge member between the first instrument guide member and the second instrument guide member, the central instrument guide member configured to receive a third surgical instrument.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application61/765,482 filed Feb. 15, 2013, which is incorporated by referenceherein in its entirety.

FIELD

The present disclosure is directed to surgical systems and methods foruse in minimally invasive robotically assisted surgery, and moreparticularly to systems and methods for moving a surgical instrumentabout a pivot located proximally of an anatomical entry point.

BACKGROUND

Minimally invasive medical techniques are intended to reduce the amountof extraneous tissue that is damaged during diagnostic or surgicalprocedures, thereby reducing patient recovery time, discomfort, anddeleterious side effects. Minimally invasive robotic surgical ortelesurgical systems have been developed to increase a surgeon'sdexterity and to avoid some of the limitations on traditional minimallyinvasive techniques. In telesurgery, the surgeon uses some form ofremote control, e.g., a servomechanism or the like, to manipulatesurgical instrument movements, rather than directly holding and movingthe instruments by hand. In telesurgery systems, the surgeon can beprovided with an image of the surgical site at the surgical workstation.While viewing a two or three dimensional image of the surgical site on adisplay, the surgeon performs the surgical procedures on the patient bymanipulating master control devices, which in turn control motion of theservomechanically operated instruments.

In robotically-assisted telesurgery, the surgeon typically operates amaster controller to control the motion of surgical instruments at thesurgical site from a location that may be remote from the patient (e.g.,across the operating room, in a different room, or a completelydifferent building from the patient). The master controller usuallyincludes one or more hand input devices, such as hand-held wristgimbals, joysticks, exoskeletal gloves or the like, which areoperatively coupled to the surgical instruments that are releasablycoupled to a patient side surgical manipulator (“the slave”). The mastercontroller controls the instrument's position, orientation, andarticulation at the surgical site. The slave is an electro-mechanicalassembly which includes one or more arms, joints, linkages, servomotors, etc. that are connected together to support and control thesurgical instruments. In a surgical procedure, the surgical instruments(including an endoscope) may be introduced directly into an opensurgical site, through a natural orifice, or through cannulas into abody cavity.

For minimally invasive surgical procedures, the surgical instruments,controlled by the surgical manipulator, may be introduced into the bodycavity through a single surgical incision site, multiple closely spacedincision sites on the patient's body, and/or one or more naturalorifices in the patient anatomy. For some minimally invasive surgicalprocedures performed through particularly small entry ports, multiplesurgical instruments may be introduced in a closely gathered clusterwith nearly parallel instrument shafts. Previous surgical systems andtechniques maintained a common center of motion, known as a “remotecenter,” at an area near the anatomical entry point. Attempts tomaintain a center of rotation at the anatomical entry point, through aparticularly narrow surgical incision or a particularly narrow naturalorifice such as a human throat or cervix, may result in the collision ofthe proximal ends of the surgical instruments. Improved systems andmethods are needed for controlling these surgical instruments whileminimizing the occurrence of surgical instrument collisions.

SUMMARY

The embodiments of the invention are summarized by the claims thatfollow below.

In one embodiment, a robotic surgical system comprises an instrumentchassis having a proximal mounting section and a distal mountingsection. The system also comprises an instrument guide movably coupledto the distal mounting section and an actuator coupled to the proximalmounting section. A linkage system operably interconnects the actuatorand the instrument guide to transmit motion from the actuator to theinstrument guide.

In another embodiment, a robotic surgical method comprises providing aninstrument chassis having a proximal mounting section and a distalmounting section. An instrument guide assembly is movably coupled to thedistal mounting section. A pair of proximal actuators are coupled to theproximal mounting section, and a linkage system operably interconnectsthe actuators and the instrument guide assembly. The method furtherincludes providing first control signals to one of the proximalactuators to cause the linkage system to move the instrument guideassembly in a first rotational degree of freedom. The method alsoincludes providing second control signals to the other one of theproximal actuators to cause the linkage system to move the instrumentguide assembly in a second rotational degree of freedom.

In another embodiment, a robotic surgical system comprises an instrumentchassis assembly having a proximal mounting section and a distalmounting section. The chassis includes an instrument interface coupledto the proximal mounting section. The surgical system further comprisesan actuation system coupled to the proximal mounting section. Thesurgical system further comprises a linkage system operably coupledbetween the actuation system and the distal mounting section. Thelinkage system includes an instrument guide. The surgical system furtherincludes a surgical instrument configured to couple with the instrumentinterface and the instrument guide.

BRIEF DESCRIPTIONS OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isemphasized that, in accordance with the standard practice in theindustry, various features are not drawn to scale. In fact, thedimensions of the various features may be arbitrarily increased orreduced for clarity of discussion. In addition, the present disclosuremay repeat reference numerals and/or letters in the various examples.This repetition is for the purpose of simplicity and clarity and doesnot in itself dictate a relationship between the various embodimentsand/or configurations discussed.

FIG. 1 is a schematic depiction of a robotic surgical system accordingto an embodiment of the present disclosure.

FIGS. 2A, 2B, and 2C are a schematic depictions of a minimally invasivesurgical system according to embodiments of the present disclosure.

FIG. 3 is a perspective view of a minimally invasive surgical systemaccording to another embodiment of the present disclosure.

FIG. 4 is a schematic depiction of an instrument interface of a roboticsurgical system according to an embodiment of the present disclosure.

FIG. 5 is a method of robotic surgery according to an embodiment of thepresent disclosure.

FIG. 6 is a side view a distal end of a surgical instrument according toan embodiment of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description of the embodiments of theinvention, numerous specific details are set forth in order to provide athorough understanding of the disclosed embodiments. However, it will beobvious to one skilled in the art that the embodiments of thisdisclosure may be practiced without these specific details. In otherinstances well known methods, procedures, components, and circuits havenot been described in detail so as not to unnecessarily obscure aspectsof the embodiments of the invention.

Referring to FIG. 1 of the drawings, a robotic surgical system isgenerally indicated by the reference numeral 100. The robotic surgicalsystem 100 includes a master system 102, also referred to as a master orsurgeon's console, for inputting a surgical procedure and a slave system104, also referred to as a patient-side manipulator (PSM), forrobotically moving surgical instruments at a surgical site within apatient. The robotic surgical system 100 is used to perform minimallyinvasive robotic surgery. One example of a robotic surgical systemarchitecture that can be used to implement the systems and techniquesdescribed in this disclosure is a da Vinci® Surgical System manufacturedby Intuitive Surgical, Inc. of Sunnyvale, Calif. Alternatively, asmaller scale robotic surgical system with a single manipulator arm maybe suitable for some procedures. The robotic surgical system 100 alsoincludes an image capture system 106, which includes an image capturedevice, such as an endoscope, and related image processing hardware andsoftware. The robotic surgical system 100 also includes a control system108 that is operatively linked to sensors, motors, actuators, and othercomponents of the master system 102 and the slave system 104 and to theimage capture system 106.

The system 100 is used by a system operator, generally a surgeon, whoperforms a minimally invasive surgical procedure on a patient. Thesystem operator sees images, captured by the image capture system 106,presented for viewing at the master system 102. In response to thesurgeon's input commands, the control system 108 effects servomechanicalmovement of surgical instruments coupled to the robotic slave system104.

The control system 108 includes at least one processor and typically aplurality of processors for effecting control between the master system102, the slave system 104, and the image capture system 106. The controlsystem 108 also includes software programming instructions to implementsome or all of the methods described herein. While control system 108 isshown as a single block in the simplified schematic of FIG. 1, thesystem may comprise a number of data processing circuits (e.g., on themaster system 102 and/or on the slave system 104), with at least aportion of the processing optionally being performed adjacent an inputdevice, a portion being performed adjacent a manipulator, and the like.Any of a wide variety of centralized or distributed data processingarchitectures may be employed. Similarly, the programming code may beimplemented as a number of separate programs or subroutines, or may beintegrated into a number of other aspects of the robotic systemsdescribed herein. In one embodiment, control system 108 may supportwireless communication protocols such as Bluetooth, IrDA, HomeRF, IEEE802.11, DECT, and Wireless Telemetry.

The robotic surgical system 100 further includes an instrument chassis110 that couples to the slave system 104. The instrument chassis 110provides a common platform for coupling surgical instruments 112 andendoscope 114 for introduction into a patient entry point 116. In thisembodiment, the patient entry point is a human mouth for providingaccess to the throat or larynx. It will be appreciated that theembodiments of this disclosure may be used for accessing body tissuesthrough other natural or surgically created orifices.

FIG. 2A is a schematic depiction of a minimally invasive surgical system200 according to an embodiment of the present disclosure. The system 200includes an instrument chassis 202 having a proximal section 204 and adistal section 206. The chassis 202 supports an endoscope 216.Generally, the dimensions and shape of the chassis at its distal section206 are reduced compared to its proximal end 204 to minimize the volumeof the surgical equipment near the surgical entry point. Instrumentinterfaces 208, 210 are movably mounted to the proximal section 204 ofthe instrument chassis 202. Surgical instrument 212 is mounted at itsproximal end 213 to the instrument interface 208. Surgical instrument214 is mounted at its proximal end 215 to the instrument interface 210.The interface 208 drives movable components in the surgical instrument212 as described in U.S. Pat. No. 6,491,701 which is incorporated byreference herein, in its entirety. The interface 210 drives theinstrument 214 in a similar way. The surgical instruments 212, 214 arealso movably coupled to the distal section 206 of the chassis 202. Aswill be described in detail below, the instrument interfaces 208, 210are mounted to the proximal section 204 of the chassis 202 such thatrotational and linear motion is permitted. Specifically, an instrumentinterface mounting or a flexible instrument shaft permits a pitch motionof the instrument interfaces 208, 210 relative to the chassis 202, a yawmotion of the instrument interfaces relative to the chassis and aninsertion sliding motion of the instrument interfaces relative to thechassis. The system 200 functions similar to the manner in whichchopsticks operate, in that small motions at the proximal end of thetool, near a pivot location, can correspond to larger motions at thedistal end of the tool for manipulating objects.

An actuation system 220 operates the components of instrument 212, suchas an end effector and various wrist joints. An actuation system 222operates the components of instrument 214, such as an end effector andvarious wrist joints. The actuation systems 220, 222 may include motors,actuators, drive systems, control systems, and other components foreffecting the control of the instruments. An interface actuation system224 controls the movement of the instrument 212 with respect to thechassis 202, and an interface actuation system 226 controls the movementof the instrument 214 with respect to the chassis 202. The referencesystem X₁, Y₁, Z₁ moves with the instrument 212 and the reference systemX₂, Y₂, Z₂ moves with the instrument 214. Although the surgical system200 may be configured to manipulate two instruments as shown, however inalternative embodiments, the system may be used to control the movementof more than two instruments.

FIG. 2B is a schematic depiction of the minimally invasive surgicalsystem 200 according to another embodiment of the present disclosure. Inthis embodiment the interface actuation system 224′ includes a motor M1driving an orientation system G (e.g., a gimbal system such as shown inFIG. 3, gimbal components 334, 336) to control the proximal instrumentinterface 208 to move in a yaw movement (e.g., about the axis Y₁). Theinterface actuation system 224′ also includes a motor M2 driving theorientation system G to control the proximal instrument interface 208 tomove in a pitch movement (e.g., about the axis X₁). The interfaceactuation system 224′ also includes a motor M3 to control the proximalinstrument interface 208 to move axially along the axis Z₁ (e.g., forinstrument insertion and withdrawal). Although not shown in detail, theinterface actuation system 226′ may include similar components foreffecting similar motion in the proximal instrument interface 210. Thus,in this embodiment, the motion of the instruments may be controlled atthe proximal end without support or control at the distal end. In thisembodiment, the interface actuation systems 224′ and 226′ are betweenthe proximal instrument interfaces 208, 210. Although the surgicalsystem 200 may be configured to manipulate two instruments as shown,however in alternative embodiments, the system may be used to controlthe movement of more than two instruments.

FIG. 2C is a schematic depiction of the minimally invasive surgicalsystem 200 according to another embodiment of the present disclosure. Inthis embodiment, the interface actuation systems 224″ and 226″ aresubstantially similar to interface actuation systems 224′ and 226′,respectively, but in this embodiment, the proximal instrument interfaces208, 210 are between the interface actuation systems 224″ and 226″.Although the surgical system 200 may be configured to manipulate twoinstruments as shown, however in alternative embodiments, the system maybe used to control the movement of more than two instruments.

Earlier methods and systems of robotic surgery involved the use of asurgical instrument that was coupled to a robotic manipulator arm and toan insertion linkage system that constrained motion of the surgicalinstrument about a remote center of motion aligned along the shaft ofthe surgical instrument and coincident with a patient entry point, suchas an entry incision. Further details of these methods and systems aredescribed in U.S. Pat. Nos. 5,817,084 and 6,441,577, which areincorporated by reference herein in their entirety. The embodiments ofthis disclosure remove the constraint of the remote center of motion atthe patient entry point and permit a surgical instrument to pivot, withat least one rotational degree of freedom, about a location in spacenear or coincident with a proximal end of the surgical instrument. Theproximal pivot locations may be, for example, approximately 30 cm fromthe patient entry point when using a surgical instrument with anapproximate 40-50 cm length.

FIG. 3 is a perspective view of a minimally invasive surgical system 300according to another embodiment of the present disclosure. The system300 may be effective to avoid instrument collisions when working insmall spaces. The system 300 includes an instrument chassis 302 andinstrument interfaces 304, 306 for mounting surgical instruments 308,310, respectively to the chassis. The surgical instrument 308 includesan end effector 308 a and a wrist mechanism 308 b. The surgicalinstrument 310 includes an end effector 310 a and a wrist mechanism 310b. The surgical instruments 308, 310 move independently of one anotherbased upon control input signals originating from the master system 102and manipulator actuation signals from control system 108. The system300 further includes a chassis mounted actuator system 312 and a linkagesystem 314 interconnecting the actuator system 312 with the surgicalinstruments 308, 310. An image capture system 316 is supported by thechassis 302 and is generally aligned along a central axis 318 (in aZ-axis direction) through the chassis.

In greater detail, the instrument chassis 302 includes a proximalportion 320 and a distal portion 322. The system 300 generally includesa left lateral half 324 and a right lateral half 326 split generallyabout the central axis 318. In this embodiment, the structures andfunction of the right and left lateral halves of the system 300 aregenerally the same. Therefore, a full description of the structure andfunction of the system 300 will be directed toward the left lateral half324 with the understanding that the structures and function of the rightlateral half 326 are the same.

The instrument chassis 302 includes a bridge 328 located at a proximalend 329 of the chassis and includes a bridge 330 located at a distal end331 of the chassis. A support tube 332 extends generally along the axis318 and supports the image capture system 316. The support tube 332rigidly connects the bridges 328, 330. The components of the instrumentchassis may be formed of relatively rigid metals, plastics, or ceramics.The instrument chassis 302 further includes a gimbal support 334pivotally connected to a gimbal plate 336. The gimbal system 334, 336permits a yaw motion of the surgical instrument 308 (i.e., a rotationaldegree of freedom about a Y-direction axis) and permits a pitch motionof the surgical instrument 308 (i.e., a rotational degree of freedomabout an X-direction axis. The motion of the gimbal system 334, 336 ispassive, in that the motion is responsive to other actuated forces inthe system 300 as will be described in greater detail. In alternativeembodiments, other joint or pivot systems, including multi-axis gimbals,ball/socket joints, and hinges, may provide one or more degrees offreedom at the proximal section of the chassis.

The instrument chassis 302 also includes a guide (not shown) slidablyengaged with a track (not shown) of the instrument interface 304. Aguide 338 and track 340 are more clearly visible on the right half 326of the system 300. The guide and track of the left half 324 permitinsertion motion of the surgical instrument 308 generally along aZ-direction axis. Insertion drive systems 341 a, 341 b are coupled tothe instruments 308, 310, respectively, to provide a driven insertionmotion that moves the guide and track relative to one another. Theinsertion drive systems 341 a, 341 b include a drive motor and a drivemechanism such as a lead screw, ball screw, cable drive, or rack andpinion system. Alternatively, the motion of the guide/track may bepassive, in that the motion is responsive to other actuated forces inthe system 300.

The left half of the actuation system 312 includes actuators 340, 342coupled to the chassis 302. The actuators 340, 342 each include a motorM1, M2, respectively with a drive mechanism that provides variable andcontrollable force and position control and an encoder E1, E2,respectively for providing the control system 108 with the rotationalposition of the respective motor drive shafts. Further details of theactuation system, including suitable alternatives, are provided in U.S.Pat. No. 5,792,135 which is incorporated by reference herein in itsentirety. The actuators 340, 342 are coupled to the linkage system 314which transmits the actuation. Each actuator provides a predeterminedtype of actuation. For example, the actuator 340 provides an actuatedpitch motion (about an X-direction axis), and the actuator 342 providesan actuated yaw motion (about a Y-direction axis).

The left half of the linkage system 314 includes an actuation rod 346coupled between ball and socket joints 348, 350. The ball and socketjoint 348 is coupled to the actuator 340. The linkage system 314 alsoincludes an instrument guide 352 coupled to ball and socket joint 350.In this embodiment, the instrument guide 352 is a tubular sleeve sizedto receive the shaft of the surgical instrument 308. In alternativeembodiments, the instrument guide may be a ring, a tray, an openingtube, or other structure to movably link the surgical instrument to thechassis. The linkages 346, 348, 350 serve to transmit a motion from theactuator 340 to the instrument guide 352. Specifically, the linkages maymove the instrument guide 352 in a generally linear Y-direction or in arotational pitch motion. The linkage system 314 also includes anactuation rod 354 coupled between ball and socket joints 356 (viewobstructed by chassis), 358. The ball and socket joint 350 is coupled tothe actuator 342. The instrument guide 352 is also coupled to the balland socket joint 358. The linkages 354, 356, 358 serve to transmit amotion from the actuator 342 to the instrument guide 352. Specifically,the linkages may move the instrument guide 352 in a generallyX-direction or in a rotational yaw motion. The linkage system 314further includes a ball joint 360 positioned within a socket formed inthe distal bridge 330. The ball joint 360 is coupled to the instrumentguide 352 to tether the instrument guide to the chassis 302. Thecomponents of the linkage system may be formed of relatively rigidmetals, plastics, or ceramics. The components of the linkage system maybe sterilizable or disposable. The components of the linkage system mayhave a small cross-sectional area to minimize the volume of the surgicalequipment near the patient entry point. For example, the rod linkagesmay have a diameter of approximately 1-3 mm. In alternative embodiments,other linkage components may be suitable to transmit a predeterminedmotion. Such alternative components may include uni-directional hingejoints, saddle joints, slide joints, flexible components such assprings, and fixed joints.

The chassis 302 also supports the image capture system 316. Morespecifically, an endoscopic instrument 370 of the image capture system316 extends through the support tube 332. The endoscopic instrument 370has a viewing end 372 and is operatively connected to a viewer in themaster system 102 to display an image captured at the viewing end to thesurgeon or other viewer. The endoscopic instrument 370 may be fixedrelative to the instrument chassis 302 or may be constrained to movementalong an insertion axis generally aligned with the axis 318.Alternatively, the endoscopic instrument may be steerable, pivotable, orotherwise articulatable relative to the instrument chassis to change theviewpoint of the viewing end.

The instrument interface 304 is shown in greater detail in FIG. 4. Achassis interface plate 380 (which may be considered part of the chassisor part of the interface) is rotatably connected to an instrumentinterface plate 382. The rotational motion may be provided by a swiveljoint, a ball/socket joint, or other known mechanism to provide full orpartial rotational motion. The rotational motion between the plates 380,382 is passive, in that the motion is responsive to other actuatedforces in the system 300 as will be described in greater detail.

Actuators 384, 386, 388, 390 are operably coupled to interface discs392, 394, 396, 398, respectively. A more detailed description of theinterface discs and their function in driving a predetermined motion inan attached surgical instrument is fully described, for example, in U.S.Pat. No. 7,963,913, filed Dec. 10, 2006, disclosing “InstrumentInterface of Robotic Surgical System,” which is incorporated byreference herein in its entirety. In this embodiment, each actuatorincludes a motor M and an encoder E. Each actuator 384-390 influences aspecific motion in the end effector 308 a and/or the wrist mechanism 308b of the surgical instrument 308. As one example, the actuator 384 maycontrol a roll motion of the wrist mechanism 308 b. The actuator 386 maycontrol an actuated pitch motion of the wrist mechanism 308 b. Theactuator 388 and the actuator 390 may be coordinated to control actuatedyaw and grip motions of the wrist mechanism. The assigned controls forthe various actuators are merely examples. In alternative embodiments,the actuators may be configured to control different motions in thesurgical end effector or wrist. For example a single actuator maycontrol grip while the coordinated combination of two actuators maycontrol pitch and yaw of the wrist mechanism.

As shown in FIG. 3, the surgical instrument 308 includes a proximalhousing 394 that couples to the interface 304. An instrument shaft 396extends between the proximal housing 394 and the wrist mechanism 308 b.Various embodiments of surgical instruments, end effectors, and wristmechanisms are explained in detail in U.S. Pat. Nos. 5,792,135;6,331,181; and 6,817,974, which are incorporated by reference herein intheir entirety.

As assembled, the proximal housing 394 is coupled to the instrumentinterface 304 and the shaft 396 is inserted through the instrument guide352. The shaft 396 passively slides within the instrument guide 352, inresponse to actuated forces in the system 300. For example, actuators340, 342 may provide coupled motion for pitch about axis X and for yawabout axis Y. When the actuators 340, 342 both move in the samedirection about the axis Y, the shaft 396 moves in yaw. When theactuators 340, 342 move in different directions about the axis Y, theshaft 396 moves in pitch. The combined movement of the actuators 340,342 may be governed by a 2×2 coupling matrix to move the shaft 396 in arange of directions.

The system 300 as described, allows surgical access to body tissuesthrough small natural or surgically created patient entry points. Thesystem may be particularly suited for surgically accessing larynx orthroat tissues via an open patient mouth or for accessing uterinetissues via the cervix to perform a vaginal hysterectomy. Alternatively,the system 300 may be used to perform surgery that may be tiring for asurgeon or require awkward positioning, such as breast surgery. Ascompared to robotic surgical systems that require multiple large,dedicated manipulator arms to control rotational and insertion motionsof the surgical instruments, the system 300 uses a minimized-sizechassis that supports multiple surgical instruments. Although system 300describes the use of two surgical instruments coupled to a commonchassis, in alternative embodiments, three or more surgical instrumentsmay be mounted and controlled from a common chassis. Locating theactuation system for controlling the movement of the instrument guidesat a proximal section of the chassis minimizes the number and size ofthe structures needed at intermediate or distal locations along theinstrument shaft to support and control multiple surgical instruments.The linkage system allows the actuation system to remotely control themotion of the instrument guides.

Prior to the use of the system 300, a manipulator arm of the slavemanipulator system 104 is positioned and locked into place. Themanipulator arm may be, for example, an arm of a da Vinci® SurgicalSystem or may be a smaller scale manipulator with a linked arm having upto six degrees of freedom. In some embodiments, the manipulator armsupporting the system 300 is not controlled by motors. It may be apassive lockable arm with one or more balanced joints having brakes orlocks. A passive lockable arm may move freely in a releasedconfiguration, allowing the system to be positioned at the surgical sitein a selected orientation. The passive lockable arm is then moved to alocked configuration with brakes holding the selected orientation. Inother embodiments, the system 300 may be held by an iron intern, apassive multi-jointed unbalanced arm that may be manually locked.

Referring now to FIG. 5, a general method 400 of robotic surgery usingthe system 300 is provided. At 402, the housing 394 at the proximal endof the surgical instrument 308 is received into engagement with theinstrument interface 304. At 404, the shaft 396 of the surgicalinstrument 309 is received into the instrument guide 352 at the distalend of the instrument chassis 302. More specifically, a distal orintermediate portion of the shaft 396 is received into the instrumentguide 352. At 406, the actuation system 312 actuates linkage system 314to move the instrument guide 352 relative to the instrument chassis 302.More specifically, the actuator 340 receives control signals from thecontrol system 108 to drive the linkage system 314, including moving theball and socket joint 348 which moves the rod 346. Further, the actuator342 receives control signals from the control system 108 to drive thelinkage system 314, including moving the ball and socket joint 356 whichmoves the rod 354. When rod 346 and rod 354 move together, instrumentguide 352 moves along an X-direction axis. When rod 346 and rod 354 moveoppositely, instrument guide 352 moves along a Y-direction axis. If onlyone rod 346 or 354 is moving, instrument guide 352 moves at an angle toboth the X and Y-direction axes. The instrument guide 352 is tethered tothe distal portion 330 of the chassis 302 by the ball joint 360.

At 408, in response to the motor-driven actuation of the instrumentguide 352, the proximal end of the surgical instrument 308 is permittedto passively move in multiple rotational degrees of freedom. Morespecifically, the proximal end of the surgical instrument 308 ispermitted to passively rotate (yaw) with the gimbal plate 336 about aY-direction axis. Additionally, the proximal end of the surgicalinstrument 308 is permitted to passively rotate (pitch) with theinstrument interface plate 382 relative to the chassis interface plate380 about an X-direction axis. Because of the proximal location of thepassive rotational joints, the movement of the instrument guide 352 neara distal or intermediate location of the instrument shaft 396 affects asmaller scale motion at the proximal end of the surgical instrument 308.The smaller scale motion at the proximal end of the surgical instrumentsreduces or prevents proximal end instrument collisions. To avoid roboticarm collisions, some existing systems may require spacing betweeninstrument anatomic entry points of approximately 8-9 cm. The systems ofthis disclosure may allow closer instrument spacing while avoidingrobotic arm collisions.

In an alternative embodiment, one or more of the gimbals or otherrotational joints at the proximal end of the chassis may be replacedwith fixed joints. In this embodiment, a flexible instrument shaft maybe used, allowing the surgical instrument a limited amount of rotationalmovement relative to the chassis.

To provide additional degrees of freedom to the surgical instrument andto increase the workspace between to relatively parallel instrumentsinserted into a narrow patient entry point, a parallel motion mechanismor “joggle joint” may be added to the distal end of the surgicalinstrument. The parallel motion mechanism includes a series of jointsand linkages at the distal of the surgical instrument, proximal of theend effector, that permit lateral displacement of the end effector. Adescription of joggle joints and parallel motion mechanisms is providedin U.S. Pat. No. 7,942,868 and U.S. patent application Ser. No.12/489,566 which are incorporated by reference herein in their entirety.FIG. 6 is a side view of a distal surgical instrument section 500 with ashaft 501. The section 500 includes a joint 502, a joint 504, a joint506, and linkages 508, 510. The joints 502, 504 permit +/−45° ofrotation and the joint 510 permits +/−90° of rotation. The joints 502,504, 506 and linkages 508, 510 provide a lateral displacement D from theaxis of the shaft 510, allowing for a greater surgical workspace betweengenerally parallel surgical instruments.

One or more elements in embodiments of the invention may be implementedin software to execute on a processor of a computer system such ascontrol system 108. When implemented in software, the elements of theembodiments of the invention are essentially the code segments toperform the necessary tasks. The program or code segments can be storedin a processor readable storage medium or device that may have beendownloaded by way of a computer data signal embodied in a carrier waveover a transmission medium or a communication link. The processorreadable storage device may include any medium that can storeinformation including an optical medium, semiconductor medium, andmagnetic medium. Processor readable storage device examples include anelectronic circuit; a semiconductor device, a semiconductor memorydevice, a read only memory (ROM), a flash memory, an erasableprogrammable read only memory (EPROM); a floppy diskette, a CD-ROM, anoptical disk, a hard disk, or other storage device, The code segmentsmay be downloaded via computer networks such as the Internet, Intranet,etc.

Note that the processes and displays presented may not inherently berelated to any particular computer or other apparatus. Variousgeneral-purpose systems may be used with programs in accordance with theteachings herein, or it may prove convenient to construct a morespecialized apparatus to perform the operations described. The requiredstructure for a variety of these systems will appear as elements in theclaims. In addition, the embodiments of the invention are not describedwith reference to any particular programming language. It will beappreciated that a variety of programming languages may be used toimplement the teachings of the invention as described herein.

While certain exemplary embodiments of the invention have been describedand shown in the accompanying drawings, it is to be understood that suchembodiments are merely illustrative of and not restrictive on the broadinvention, and that the embodiments of the invention not be limited tothe specific constructions and arrangements shown and described, sincevarious other modifications may occur to those ordinarily skilled in theart.

1-28. (canceled)
 29. An instrument chassis for a robotic surgicalsystem, the instrument chassis comprising: a bridge member; a firstinstrument guide member configured to receive a first surgicalinstrument; and a second instrument guide member configured to receive asecond surgical instrument, wherein each of the first instrument guidemember and the second instrument guide member is moveably coupled to thebridge member such that each of the first instrument guide member andthe second instrument guide member is moveable in at least one degree offreedom relative to the bridge member; and a central instrument guidemember coupled to the bridge member between the first instrument guidemember and the second instrument guide member, the central instrumentguide member configured to receive a third surgical instrument.
 30. Theinstrument chassis of claim 29, wherein each of the first instrumentguide member and the second instrument guide member is slidably movablerelative to the bridge member.
 31. The instrument chassis of claim 29,wherein each of the first instrument guide member and the secondinstrument guide member is pivotably moveable relative to the bridgemember.
 32. The instrument chassis of claim 29, wherein the bridgemember is rigidly coupled to a proximal chassis by a support sectionextending between the bridge member and the proximal chassis.
 33. Theinstrument chassis of claim 29, wherein the third surgical instrument isan image capture device.
 34. The instrument chassis of claim 29, whereinthe third surgical instrument extends through the central instrumentguide member along a central chassis axis.
 35. The instrument chassis ofclaim 29, wherein the third surgical instrument is slidably moveablerelative to the central instrument guide member.
 36. The instrumentchassis of claim 29, wherein the central instrument guide member ismoveable in at least one degree of freedom relative to the bridgemember.
 37. A surgical system comprising: an arm of a manipulatorsystem; and an instrument chassis including a bridge member positionedproximal a patient entry site; a first surgical instrument including aproximal portion and a distal portion; and a first instrument guidemember coupled to the bridge member and moveable relative to the bridgemember in at least one degree of freedom, wherein the first instrumentguide member is adapted to receive the distal portion of the firstsurgical instrument, and wherein the arm is configured to interface withthe proximal portion of the first surgical instrument to move the firstsurgical instrument relative to the bridge member in the at least onedegree of freedom.
 38. The surgical system of claim 37, wherein thefirst instrument guide member is slidably movable relative to the bridgemember.
 39. The surgical system of claim 37, wherein the firstinstrument guide member is pivotably moveable relative to the bridgemember.
 40. The surgical system of claim 37, wherein the bridge memberis rigidly coupled to a proximal chassis by a support section extendingbetween the bridge member and the proximal chassis.
 41. The surgicalsystem of claim 37, wherein the distal portion of the first surgicalinstrument is slidably movable relative to the first instrument guidemember.
 42. The surgical system of claim 37, further comprising acentral instrument guide member coupled to the bridge member, thecentral instrument guide member configured to receive a third surgicalinstrument, wherein the third surgical instrument is an image capturedevice.
 43. The surgical system of claim 42, wherein the third surgicalinstrument extends through the central instrument guide member along acentral chassis axis.
 44. The surgical system of claim 43, wherein thethird surgical instrument is slidably moveable relative to the centralinstrument guide member.
 45. The surgical system of claim 42, whereinthe central instrument guide member is moveable in at least one degreeof freedom relative to the bridge member.
 46. A robotic surgical systemcomprising: a bridge member; a surgical instrument including a shaft,the surgical instrument defining a central instrument axis; and aninstrument guide member coupled to the bridge member, the instrumentguide member configured to receive the shaft of the surgical instrumentand to moveably couple the surgical instrument to the bridge member suchthat the central instrument axis is moveable in at least one degree offreedom relative to the bridge member.
 47. The robotic surgical systemof claim 46, wherein the instrument guide member is at least one ofslidably moveable relative to the bridge member or pivotably moveablerelative to the bridge member.
 48. The robotic surgical system of claim47, wherein the shaft of the surgical instrument is slidably moveablerelative to the instrument guide member.